def heapify(arr, n, i): 
    largest = i  
    l = 2 * i + 1
    r = 2 * i + 2
  
    if l < n and arr[i] < arr[l]: 
        largest = l 

    if r < n and arr[largest] < arr[r]: 
        largest = r 

    if largest != i: 
        arr[i], arr[largest] = arr[largest], arr[i]
        heapify(arr, n, largest) 

def heapSort(arr): 
    n = len(arr) 
  
    # Build a maxheap. 
    for i in range(n, -1, -1): 
        heapify(arr, n, i) 
  
    for i in range(n-1, 0, -1): 
        arr[i], arr[0] = arr[0], arr[i]   # 交换
        heapify(arr, i, 0) 
  
arr = [100, 200, 120, 80, 50, 150, 20, 160, 90, 130] 
heapSort(arr) 
n = len(arr) 
print ("排序后") 
print(arr)
